1. Field of the Invention
The field of this invention relates to dissolution testing equipment for determining the dissolving rate of drugs encapsulated in the form of a tablet, capsule or caplet which are commonly known as pills and more particularly to a media dispensing apparatus to be used in conjunction with a dissolution test apparatus.
2. Description of the Prior Art
Drugs are commonly manufactured in the form of pills. The reason for using pills is that when the drug is swallowed by a human, the drug will be disseminated into the body over a period of time as the pill dissolves. Manufacturers of pills are required by law to determine the precise dissolving characteristics of their pill before it is placed on the market. In order to determine the dissolving characteristics, dissolution test equipment is utilized. Although dissolution test equipment is commonly used in conjunction with drugs designed for human consumption, it is considered to be within the scope of this invention to use it with other animals such as horses, cows, rabbits, cats, dogs, monkeys and so forth.
Every known form of dissolution testing equipment generally utilizes a plurality of liquid containing flasks called testing vessels. In each flask is to be placed a liquid called, media, with the media essentially duplicating the liquid solution that is contained within the stomach of the human body. A precise quantity of the solution is placed within the flask. The pill is then inserted within the flask and the time of the insertion then noted. A mixing paddle is inserted within the flask with mixing at a precise rate then occurring. The mixing procedure is to duplicate the natural turbulence that is created within the stomach of the human. Aliquots are removed from the solution at precise time intervals with these aliquots then being analyzed to determine the amount of drug that has been dissolved within the solution in relation to the time that the pill has been in solution.
In order to insure that the testing process is accomplished as accurately and as quickly as possible, such dissolution testing apparatus in the past has been designed as follows:
1. Normally the dissolution testing apparatus will have six or eight flasks. Dissolution testing of the pill is accomplished simultaneously in all six or eight flasks with each flask to receive a pill. The average dissolving rate is then calculated between the flasks.
2. The flasks are placed in a bath with this bath to be maintained at a precise temperature. The temperature level is to essentially duplicate the temperature of the stomach liquid within the human.
In the past, the procedure in conjunction with the six or eight flasks is for the technician to take media at the precise temperature and fill each flask accurately to a precise level. This precise filling of each of the flasks is difficult if this procedure is completed manually. Additionally, it is important that the media be deaerated, and with this manual filling technique, no deaeration of the media takes place.
In the past, there has been designed a media dispensing apparatus which facilitated the dispensing of a precise quantity of media into each of the flasks of the dissolution test equipment. However, one of the disadvantages of such a piece of equipment in the past has been that it has been not readily portable, therefore could not be easily transported from one dissolution test apparatus to another. Also, the measuring system for determining volume that is being supplied into each flask is not that precise. It is important that each of the flasks within the dissolution test apparatus have exactly the same volume. Also, there was no provision for heating of the media to a precise temperature.
A typical dissolution test apparatus is shown and described within U.S. Pat. No. 5,639,974 which was issued on Jun. 17, 1997. However, the media dispensing apparatus of this patent application can be effectively used with numerous other types of dissolution test apparatus and it is not intended to be used solely with the dissolution test apparatus of the aforementioned patent.